Best defense I have against any fungal infection is a warm shower with soap right after training. Here at PKG we have a small dressing room and 1 shower but it is still enough for me to be able to take a shower after each practice. It is not %100 but will lower the chances of staph and ringworm to a minimum.
Ps: I have eczema so I am prone to getting ringworm and I can't kill it with lotrimin etc.. I end up using prescription pills and stuff, so shower has been the best option for me so far. Believe it or not there is a difference between showering right after and showering at home 2 hours after the training was over. Every second you spend with that fungus on your skin or staph over a superficial cut on your skin, you are increasing the chances of it to make its way under the skin and develop there.